1. Field
The present disclosure generally relates to methods and apparatus for determining the quality of a network, and more particularly to determining quality of service (QoS) of a specified local area network (LAN) and an associated network backhaul link for transmitted voice data (e.g., Voice over IP), which may be used for execution of corrective action to improve the QoS when specified parameters for the QoS are not met, as an example.
2. Background
In communication systems, the utilization of Internet Protocol (IP) telephony, such as end-to-end Voice over IP (VoIP) calls, is ever increasing. The routing between end points involved in such VoIP calls will typically access an IP network (e.g., the Internet) through any one or a combination of a number of different communication network technologies. Examples of types of network technologies used may include Wireless Local Area Networks (WLAN) such as Wi-Fi (IEEE Std. 802.11) and femtocells, or Wireless Wide Area Networks (WWAN) including cellular networks such as 1X-EVDO, High Speed Packet Access (HSPA), and other WWANs such as WiMAX (IEEE 802.16), and still other various known and to-be-defined network technologies. Accordingly, VoIP traffic may be exchanged over numerous networks in the routing between the end points. For example, in an end-to-end VoIP call between a user A and a user B in a residential setting, the VoIP packets can potentially traverse user A's Wi-Fi access network, user A's DSL or cable broadband, an IP core network, user B's DSL or cable broadband, and user B's Wi-Fi access network. It is axiomatic that as numerous networks are used to link the voice packets between the end points, a failure in the quality of service on any of these network links will affect the overall quality of service for the call.
Accordingly, it is known to determine quality of service (QoS) metrics of a communication link, and further to employ the QoS determination for taking action to improve the QoS, such as through handoff triggering for end devices from a communication link experiencing degradation of QoS to another communication link in order to maintain voice call continuity. In such systems, the QoS is typically monitored by one or both of the devices at the end points of a voice call (e.g., a mobile phone or a computer), since such devices are affected by QoS degradation occurring anywhere within the particular networks utilized to route the call.
A known metric for determining QoS in wireless local area networks (WLANs) is a determination or measurement of the received signal power in the downlink from a wireless access point (AP) to a communication device wirelessly linked to the AP. Accordingly, when the received signal power falls below a threshold value, an end device may, for example, trigger a handoff to another network, such as a wireless wide area network (WWAN) or another wireless local area network, if available. This physical (PHY) layer metric alone, however, is not efficacious for determining the total path quality for all situations and layers. For example, given a VoIP call occurring in a Wireless Local Area Network (WLAN), although the downlink radio signal strength is good for maintaining a high QoS, lost packets at the medium access control (MAC) or application layers will nonetheless adversely affect the actual QoS. Furthermore, degradation in the backhaul link from the WLAN access point to the call termination equipment will also adversely affect QoS, even though the WLAN radio signal strength is acceptable. Also, the Access Point may not receive similar power level from the communication device, resulting in a good link on the downlink and poor link on the uplink, which can not be detected by the device. Good WLAN quality, for example, requires thorough monitoring of the various points of failure (i.e., various metrics) and triggering of a handoff to another radio technology as soon as the WLAN or accompanying backhaul shows signs of failure. Accordingly, there is need for a mechanism to accurately assess the QoS at a communication terminal for the various metrics affecting the call path, thus affording optimization and convergence on the best communication protocol for a user in order to provide for seamless transit between networks and/or protocols.